Recording method, recording apparatus, and record medium

ABSTRACT

A recording method for recording data to a disc shaped record medium corresponding to a hierarchical file system is disclosed, that comprises the steps of recording management information for managing the hierarchical structure of the file system to a predetermined area of the disc shaped record medium, and treating an unused area of the predetermined area as a special file.

BACKGROUND OF THE INVENTION

[0001] 1. Field of the Invention

[0002] The present invention relates to a recording method and arecording apparatus for recording data to a disc shaped rewritablerecord medium having a large record capacity. The present invention alsorelates to such a record medium.

[0003] 2. Description of the Related Art

[0004] In recent years, high density optical discs such as a DVD(Digital Versatile Disc) have been developed and standardized. A logicalformat referred to as UDF (Universal Disc Format) has been proposed. Fora DVD-RAM (DVD-Random Access Memory), the UDF is used. The UDF can bealso applied to a CD-R that is a writable disc of a CD-ROM (Compact DiscRead Only Memory) and a CD-RW that is a rewritable disc thereof.

[0005] In the UDF, a hierarchical file system is used. Corresponding toinformation stored in the root directory, a sub directory and asubstantial file thereof are referenced. Corresponding to informationstored in the sub directory, another sub directory and a substantialfile thereof are referenced.

[0006] Next, the hierarchical file system of the UDF will be describedin detail. In the record area of the disc, data is accessed sector bysector. In the DVD-RAM, the record area is accessed from the innerperiphery to the outer periphery of the disc. A volume information areais formed from the innermost periphery of the disc to the lead-in areathereof. The volume information area is referred to as system area. Thesystem area represents the position of a file entry (FE) of the rootdirectory. The FE is composed of an allocation descriptor (AD). The ADis information represents the address and length of a root directory, asub directory, or a file.

[0007] The AD of the FE of the root directory represents the logicaladdress and length of the root directory as a substance. The rootdirectory contains at least one file identifier descriptor (FID). TheFID references the FE of a sub directory contained in the root directoryand the FE of a file contained in the sub directory. These FEs referencerespective substances of the sub directory and the file. The substanceof the sub directory contains at least one FID. In other words, in theUDF, except for the root directory, corresponding to FIDs and FEs aspointers, FIDs, FEs, and substances are successively accessed.

[0008] In the UDF, the above-described FIDs, FEs, and substances can bewritten in any recordable area. Even if information of sub directoriesand files are related, their FIDs, FEs, and substances can be written todifferent addresses. The addresses of the FIDs, FEs, and substances maybe assigned regardless of the access order.

[0009]FIG. 1 shows an example of a data assignment on a disccorresponding to the conventional UDF. Referring to FIG. 1, a lead-inarea 201 is formed on the innermost periphery of a disc 200. A systemarea 202 is formed outside the lead-in area 201. For example, asubstance 203 of a root directory is formed outside the system area 202.

[0010] Next, as an example, the case of which a file is accessed fromthe root directory through a sub directory will be described.Corresponding to the FID of the substance 203 of the root directory, anFE 204 of a sub directory at an address that is physically apart fromthe substance 203 of the root directory is referenced. Corresponding toan AD of the FE 204 of the sub directory, a substance 205 of a subdirectory at an address that is physically apart from the FE 204 of thesub directory is referenced. Likewise, an FID of the substance 205 ofthe sub directory is referenced. An FE 206 of a file at an address thatis physically apart form the substance 205 of the sub directory isreferenced. Corresponding to the AD of the FE 206 of the file, asubstance 207 of a file at an address that is physically apart from theFE 206 of the file is referenced.

[0011] As another example, in the case of which a file is directlyreferenced from the root directory, the FID of the substance 203 of theroot directory is referenced. An FE 208 of a file at an address that isphysically apart from the substance 203 of the root directory isreferenced. Corresponding to an AD of the FE 208, a substance 209 of afile at an address that is physically apart from the FE 208 of the fileis referenced.

[0012] Conventionally, when information of directories and files isscattered on a disc, the information cannot be quickly read.

[0013] In other words, when one file is accessed with reference topointers at different addresses, the disc seek time becomes long. Inother words, information on the disc cannot be quickly accessed. Inparticular, this problem is serious in a disc shaped record medium whoseaccess time is longer than a hard disk or the like.

[0014] To solve such a problem, pointer information such as FIDs and FEsmay be recorded together in a predetermined area. However, in such acase, when a file is deleted from a disc, since an FE thereof isdeleted, another file may be written to a blank address for the FE. Insuch a situation, the pointer information recorded in the predeterminedarea may be separated. As a result, the above-described problem willtake place.

OBJECTS AND SUMMARY OF THE INVENTION

[0015] Therefore, an object of the present invention is to provide arecording method, a recording apparatus, and a record medium that allowa file to be always quickly accessed free of separation of pointerinformation.

[0016] A first aspect of the present invention is a recording method forrecording data to a disc shaped record medium corresponding to ahierarchical file system, comprising the steps of recording managementinformation for managing the hierarchical structure of the file systemto a predetermined area of the disc shaped record medium, and treatingan unused area of the predetermined area as a special file.

[0017] A second aspect of the present invention is a recording apparatusfor recording data to a disc shaped record medium corresponding to ahierarchical file system, comprising a means for recording managementinformation for managing the hierarchical structure of the file systemto a predetermined area of the disc shaped record medium, and a meansfor treating an unused area of the predetermined area as a special file.

[0018] A third aspect of the present invention is a disc shaped recordmedium for recording data corresponding to a hierarchical file system,wherein management information for managing the hierarchical structureof the file system is recorded at a predetermined area, and wherein anunused area of the predetermined area is treated as a special file.

[0019] As was described above, according to the present invention, whendata is recorded on a disc shaped record medium corresponding to ahierarchical file system, management information for managing thehierarchical structure of the file system is recorded in a predeterminedarea of the record medium. In addition, an unused area of thepredetermined area is treated as a special file. As a result, managementinformation can be securely added can be secured in the predeterminedarea.

[0020] These and other objects, features and advantages of the presentinvention will become more apparent in light of the following detaileddescription of a best mode embodiment thereof, as illustrated in theaccompanying drawings.

BRIEF DESCRIPTION OF THE DRAWINGS

[0021]FIG. 1 is a schematic diagram showing an example of a dataassignment on a disc corresponding to the conventional UDF;

[0022]FIG. 2 is a schematic diagram showing a logical format of a discshaped record medium according to the present invention;

[0023]FIG. 3 is a schematic diagram showing an example of the content ofa volume information area;

[0024]FIG. 4 is a schematic diagram for explaining a managing method fora directory, a file, and a blank area according to the presentinvention;

[0025]FIG. 5 is a schematic diagram for explaining a managing method fora directory, a file, and a blank area according to the presentinvention;

[0026]FIGS. 6A to 6E are schematic diagrams for explaining a method forplacing an EIF in an area DAN-2;

[0027]FIGS. 7A to 7D are schematic diagrams for explaining a method foradding a sub directory after a format process is performed;

[0028]FIG. 8 is a schematic diagram for explaining a process for addinga file to the root directory;

[0029]FIG. 9 is a schematic diagram showing areas DAN-2′ and DAN-3′ thatare newly added; and

[0030]FIG. 10 is a block diagram showing an example of the structure ofa drive device according to the present invention.

DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS

[0031] Next, with reference to the accompanying drawings, a firstembodiment of the present invention will be described. FIG. 2 shows alogical format of a disc shaped record medium 1 according to the presentinvention. The logical format of the disc shaped record medium 1 isbased on the above-described UDF (Universal Disc Format). On theinnermost periphery of the disc shaped record medium 1 (hereinafterreferred to as disc 1), a lead-in area 10 is formed. Logical sectornumbers (LSNs) are successively assigned from the outside of the lead-inarea 10. A volume information area 11, an area DAN-1 (Data Area Number1), an area DAN-2, an area DAN-3, and a volume information area 12 aresuccessively formed. On the outermost periphery, a lead-out area 13 isformed.

[0032] Logical block numbers are assigned to the area DAN-1 to the areaDAN-3.

[0033]FIG. 3 shows an example of the content of each of the volumeinformation areas 11 and 12. The volume information area 11 contains aVRS (Volume Recognition Sequence), an MVDS (Main Volume DescriptionSequence), and a VIS (Logical Volume Sequence) corresponding to the UDF.At the end of the volume information area 11, an anchor point is placed.The content of the volume information area 11 is dually written as aRVDS (Reserve Volume Descriptor Sequence) to the volume information area12 formed inside the lead-out area 13. At the beginning and at the endof the volume information area 12, one anchor point is placed. Theanchor point at the end of the volume information area 12 corresponds tothe last logical sector number.

[0034] An area from the logical sector number 272 to (the last logicalsector number−272) is a partition area referred to as LVS (LogicalVolume Space). In the LVS, the area DAN-1 to the area DAN-3 are formed.The area DAN-1 formed on the innermost periphery side of the LVS iscomposed of an FSD (File Set Descriptor) and an SBD (Space BitmapDescriptor) corresponding to the UDF. The SBD represents blank areainformation of the disc 1 with flags for individual sectors. The areaDAN-1 represents the address of an FE of the root directory of thehierarchical structure of the file system.

[0035] The area DAN-2 is an area that contains an FE (File Entry) of adirectory and an FID (File ID) of the substance of the directory. Inother words, the FE of the directory and the FID of the substancethereof are together recorded in the area DAN-2. When a disc isformatted (that will be described later), a predetermined recordcapacity is allocated for the area DAN-2. As will be described later, anunused area of the area DAN-2 is allocated as a file with a particularattribute designated. Hereinafter, a file composed of an unused area ofthe area DAN-2 is referred to as EFI (Entry Information File). When anunused area of the area DAN-2 is treated as an EIF, the above-describedSBD is suppressed from recognizing the unused area as a blank area.

[0036] As was described in the section of Related Art Reference, an FErepresents the location (address) and size of the substance of a file ora directory. An AD (Allocation Descriptor) of the FE represents theirinformation. An FID represents the name, location (address), and size ofa file or a directory. An ICB (Information Control Block) of the FIDrepresent their information.

[0037] The area DAN-3 is an area that contains an FE of a file and thesubstance thereof. In the area DAN-3, an FE of a file and a filecorresponding to the FE are placed at successive addresses. When a fileis added, an FE of the file and the substance thereof are placed atsuccessive addresses preceded by successive addresses of an FE of anexisting file and the substance thereof. Since an FE of a file and thesubstance thereof are placed at successive addresses, the file can bequickly accessed.

[0038] Next, with reference to FIGS. 4 and 5, a method for managing adirectory, a file, and a blank area according to the present inventionwill be described. FIG. 4 is a partial view showing only the area DAN-1to the area DAN-3 shown in FIG. 2. As shown in FIG. 4, data is recordedcounterclockwise. FIG. 5 shows a hierarchical structure of FEs, FIDs,and substances.

[0039] For example, an FE of the root directory starts at LSN=a. An ADof an FE of the root directory represents the address and size of thesubstance of the root directory. The substance of the root directory andthe FE of the root directory are placed at successive addresses. Forexample, the address of the substance of the root directory is LSN=a+1.The substance of the root directory contains at least one FID. An FIDrepresents the name, address, and size of a sub directory of the rootdirectory. The FE of the sub directory and the substance of the rootdirectory are placed at successive addresses. For example, the addressof the FE of the sub directory is at LSN=a+2. An AD of the FE of the subdirectory represents the address and size of the substance of the subdirectory. The substance of the sub directory and the FE of the subdirectory are placed at successive addresses. For example, the addressof the substance of the sub directory is at LSN=a+3. The substance ofthe sub directory contains at least one FID. An FID represents the name,address, and size of a file or another sub directory.

[0040] Since FEs, FIDs, and substances are referenced as shown in FIG.5, the substance of the root directory, information of a sub directoryof the root directory, and so forth are placed at successive addressesagainst the address of the FE of the root directory at a predeterminedposition of the innermost periphery of the area DAN-2 as shown in FIG.4.

[0041] On the other hand, with reference to FIG. 5, an FID of thesubstance of the root directory represents the name, address, and sizeof an FE. An AD of an FE of an EIF represents the address and size ofthe substance of the EIF. In such a manner, since an EIF is treated as afile, as with another file, the FE represents the address and size ofthe EIF.

[0042] As shown in FIG. 6A, an FE of an EIF is placed after thesubstance of the EIF. As will be described later, the start addressand/or end address and the size of the substance of the EIF varydepending on the amount of each information written to the area DAN-2.

[0043] The FE of the root directory, the substance of the rootdirectory, the FE of the sub directory of the root directory, thesubstance of the sub directory of the root directory, the FE of the EIF,and the substance of the EIF are placed in the area DAN-2.

[0044] An FE of a file and the substance thereof are placed in the areaDAN-3. The substance of a file is an area for user data or the like. Asshown in FIG. 5, an FID of the substance of the root directoryrepresents the name, address, and size of an FE of a file. The FE of thefile is placed in the area DAN-3. At that point, the start address ofthe FE of the file is at LSN=d. An AD of the FE of the file representsthe address and size of the substance of the file. The substance of thefile and the FE of the file are placed at successive address. Forexample, the start address of the substance of the file is at LSN=d+1.

[0045] As was described above, when the disc 1 is formed, the area DAN-2is allocated. Next, an example of the format method for the disc 1 willbe described in brief. In this example, the lead-in area 10 and thelead-out area 13 are formed when the disc 1 is fabricated. The formatprocess is performed from the inner periphery to the outer periphery ofthe disc 1.

[0046] When the format process is started, the above-described VRS,MVDS, and LVIS are formed from the outside of the lead-in area 10.Thereafter, the LVS is formed. In the LVS, the area DAN-1 is formed atfirst. Thereafter, the FDS is formed and the location of the rootdirectory is designated. Thereafter, the SBD is formed. At that point,the area of the above-described EIF is treated as a used area with theSDB. As a result, the area of the EIF is allocated.

[0047] After the SBD and the area DAN-1 are formed, the area DAN-2 isformed from the outside of the area DAN-1. When the area DAN-2 isformed, corresponding to the FSD of the area DAN-1, the FE of the rootdirectory and the substance thereof are placed at predeterminedsuccessive addresses. Next, the FID of the EIF is added to the substanceof the formed root directory. The FID represents the address of the FEof the EIF.

[0048] At that point, an attribute of the EIF is designated in the FIDand the FE. Alternatively, the FID designates “hidden file attribute”.An attribute of the EIF prevents the EIF from being erased, rewritten,or moved by another device or an OS (Operating System). For example,“hidden file attribute”, “system file attribute”, and “read only fileattribute” are also designated as attributes of the EIF.

[0049] The “hidden file attribute” is an attribute that prevents a filefrom being browsed in a conventional method. The “system file attribute”is an attribute that represents that a file is a system file that isnecessary for the system. The “read only file attribute” is an attributethat represents that a file is a read-only file of which the systemprohibits the file from being changed or erased. When these threeattributes are designated to a file, the file is prohibited from beingerased, rewritten, and moved. These attributes can be removed in apredetermined manner.

[0050] Next, the FE of the EIF is formed. As was described above, the FErepresents the address and size of the file. Thus, when the FE isdesignated, a dummy file is allocated. The FE of the EIF can bedesignated with two attributes “read only file attribute” and “systemfile attribute”.

[0051] Thus, when an EIF is placed in the area DAN-2, a blank area ofthe area DAN-2 can be allocated. As was described above, after the disc1 is formatted, an FE of a sub directory and the substance thereof areplaced in the area DAN-2. At that point, the area of the EIF of the areaDAN-2 is reduced for the FE of the sub directory and the substancethereof.

[0052] As will be described later, the area DAN-2 may be formed inanother manner, not in the above-described manner. In the case, thelocations of the individual information elements in the area DAN-2 vary.

[0053] In such a manner, the area DAN-2 is formed. Although the areaDAN-3 is formed outside the area DAN-2, no process is performed for thearea DAN-3. For example, the area DAN-3 is skipped. Thereafter, the RVDSis formed. After the RVDS is formed, the format process for the disc 1is completed.

[0054] In the above example, the FE of the root directory, the substancethereof, the EIF, and the FE thereof are successively placed in the areaDAT-2. However, the present invention is not limited to such an example.According to a first embodiment of the present invention, the address ofthe FE of the EIF is fixed. The location of the FE of the EIF may be (1)before the root directory, (2) after the root directory, or (3) at theboundary between the area DAN-2 and the area DAN-3. Next, with referenceto FIGS. 6A to 6E, the method for placing the EIF in the area DAN-2 willbe described corresponding to the individual cases.

[0055]FIGS. 6A to 6E each show the area DAN-2. The area DAN-2 ispreceded by the area DAN-1 (namely, on the left side of the area DAN-2,the area DAN-1 is formed). Thus, the LSN increases to the right. InFIGS. 6A to 6E and 7A to 7D, a directory is abbreviated as “Dir”.

[0056] In FIG. 6A, the FE of the root directory and the substancethereof are placed on the beginning side of the area DAN-2. The FE ofthe EIF is placed on the end side of the area DAN-2. The substance ofthe EIF is placed between the end of the substance of the root directoryand the beginning of the FE of the EIF. In the example shown in FIG. 6A,the FID of the EIF of the substance of the root directory represents theaddress of the FE of the EIF placed on the end side of the area DAN-2.The FE of the EIF represents the start address of the substance of theEIF. In other words, the FE of the EIF is preceded by the substance ofthe EIF.

[0057] In the example shown in FIG. 6A, information (the FE and thesubstance) of a sub directory is added after the substance of the rootdirectory placed in the area DAN-2. The substance of the EIF is reducedfrom the beginning for the information of the sub directory. As aresult, the start address of the EIF written in the AD of the FE of theEIF is rewritten.

[0058] In the example shown in FIG. 6A, when the address of the FE ofthe EIF is pre-designated, the EIF can be accessed without need toreference the FID of the substance of the root directory. Thus, the FIDcorresponding to the EIF of the substance of the root directory isprevented from being rewritten. Consequently, even if the FE of the EIFis rewritten due to a particular reason, unless the FID of the EIF islost, the EIF can be easily restored.

[0059]FIG. 6B shows an example of which the FE of the EIF and thesubstance thereof are placed on the beginning side of the area DAN-2 andthe substance of the root directory and the FE thereof are placed on theend side of the area DAN-2. The FID of the substance of the rootdirectory represents the FE of the EIF. The AD of the FE of the EIFrepresents the substance of the EIF.

[0060] In the example shown in FIG. 6B, the substance of the EIF isreduced from the beginning for the information of the sub directory thatis added to the area DAN-2. As a result, the FE of the EIF is rewritten.In the example shown in FIG. 6B, the FE of the root directory placed onthe end side of the area DAN-2 is designated after the format process isperformed. For example, after the format process is performed, the rootdirectory is placed. At that point, the FE of the root directory isplaced.

[0061] Normally, in a computer system, a disc is accessed from the rootdirectory. Thus, as shown in FIG. 6B, when the FE of the EIF and thesubstance thereof are placed after the FE of the EIF and the substancethereof, the FE of the root directory and the substance thereof aresecured against the FE of the EIF and the substance thereof.

[0062] Likewise, FIG. 6C shows an example of which the FE of the EIF isplaced before the FE of the root directory. In other words, the FE ofthe EIF and the FE of the root directory are placed on the beginningside of the area DAN-2. Thereafter, the substance of the root directoryand the substance of the EIF are placed and the FE of the root directoryand the substance thereof are placed on the end side of the area DAN-2.FIG. 6E shows an example of which the FE of the root directory and thesubstance thereof are placed on the beginning side of the area DAN-2 andthe FE of the EIF and the substance thereof are placed on the end sideof the area DAN-2.

[0063] Next, the method for adding a sub directory after the formatprocess will be described in detail. As was described above, the FE ofthe sub directory and the substance thereof are placed in a reduced areaof the substance of the EIF of the area DAN-2. Next, with reference toFIGS. 7A to 7D, the example in the case shown in FIG. 6A will bedescribed. Information elements shown in FIGS. 7A to 7D are same asthose shown in FIGS. 6A to 6E.

[0064]FIG. 7A shows the content of the area DAN-2 in the state that theformat process has been just performed. FIG. 7A corresponds to FIG. 6A.In the state shown in FIG. 7A, a sub directory is added. As shown inFIG. 7B, an FID that represents the sub directory is added after thesubstance of the root directory. At that point, the size of the area ofthe substance of the EIF is reduced. In reality, when the last sector ofthe substance of the root directory becomes full, the substance of theEIF is reduced. Otherwise, it is not necessary to reduce the substanceof the EIF.

[0065] Thereafter, to add the FE of the sub directory, the size of theEIF is further reduced (see FIG. 7C). In this case, it is necessary toreduce the size of the substance of the EIF. In addition, as shown inFIG. 7D, to add the substance of the sub directory, the size of the EIFis further reduced. In addition, to reflect the change of the size ofthe substance of the EIF, the information of the FE of the EIF isrewritten.

[0066] In the above example, the case of which a sub directory is addedwas described. However, it should be noted that this method can beapplied to the case of which a file is added to the root directory.

[0067] As with the example shown in FIG. 6E, the FE of the EIF may beplaced at the location of the FE of the sub directory. In such a case,it is necessary to move the FE of the EIF to another sector and thenupdate the address information of the FID corresponding to the EIF. Inthe structure shown in FIG. 6A, such a process is not required.

[0068] Next, with reference to FIG. 8, a process for adding a file tothe root directory will be described. As was described above, an FE of afile and the substance thereof are placed in the area DAN-3. When a fileis added to the root directory, an FID of the file is written to thesubstance of the root directory. When necessary, the size of the EIF ofthe area DAN-2 is reduced. As a result, the FE of the EIF is rewritten.

[0069] The FE of the file (file A) that is added is placed at an addressrepresented by the FID added to the substance of the root directory. Thesubstance of the file A and the FE of the file A are placed atsuccessive addresses. When files B, C, and so forth are written to thedisc, the FE of the file B is placed after the end of the substance ofthe file A. The FE of the file B and the substance thereof are placed atsuccessive addresses. This operation applies to the file C. In otherwords, the substance of the file B and the FE of the file C are placedat successive addresses. The FE of the file C and the substance thereofare placed at successive addresses.

[0070] Since the substance of a file is placed just after the FEthereof, the file can be successively accessed. When a plurality offiles are successively placed, they can be more quickly accessed.

[0071] When many sub directories are added to the root directory of thearea DAN-2, many FIDs of the substance of the root directory, many FEsof sub directories, and many substances thereof are added. As a result,the area DAN-2 to become full with the FIDs, FEs and substances of thesub directories.

[0072] To solve such a problem, according to the present invention, whenthe disc 1 has a sufficient space, new areas DAN-2 and DAN-3 can beformed after the end of files of the area DAN-3. Hereinafter, the areasDAN-2 and DAN-3 that are newly formed are referred to as areas DAN-2′and DAN-3′, respectively.

[0073]FIG. 9 shows the area DAN-2′ and the area DAN-3′. The area DAN-2′is formed in such a manner that an AD′ is added after the AD of the FEof the EIF in the area DAN-2′ and thereby the size of the EIF isincreased. The AD′ represents the address of the end of the files of thearea DAN-3 and the size of the EIF′ added as the area DAN-2′. The areaDAN-3′ is formed after the substance of the EIF′. The FE and thesubstance of the sub directory added to the root directory are writtento the area DAN-2′. The file is written in the area DAN-3′.

[0074] At that point, the SBD of the area DAN-1 is rewrittencorresponding to the EIF′ placed in the area DAN-2′. As a result, thearea of the EIF′ placed in the area DAN-2′ is allocated.

[0075] The EIF may be destroyed due to a particular to reason. When theEIF is destroyed, the substance of the FE of the sub directory is notlost. At that point, a blank area of the area DAN-2 is unallocated. Thesubstance of the file is written in the area DAN-2. Thus, when the EIFis destroyed, it should be restored.

[0076] The EIF is restored as follows. For example, when the EIF iserased and a file is added to the same directory, the FID of the EIF ofthe substance of the root directory is erased.

[0077] In the first case, only the FID of the substance of the rootdirectory may be erased. The location of the FE of the EIF may be left.In addition, the location of the FE of the EIF may be known. In thatcase, the FID of the EIF is created corresponding to the FE of the EIF.The created FID is added to the substance of the root directory. As aresult, the EIF is restored.

[0078] In the second case, the location of the FE of the EIF may beunknown. In that case, all the area DAN-2 is scanned and re-calculatedso as to extract the remaining portion of the EIF. By calculating thedifference between the extracted portion and the area DAN-2, the area ofthe EIF can be obtained. Since the EIF is allocated as a single area inthe area DAN-2, such a restoring method can be used.

[0079]FIG. 10 shows an example of the structure of a drive deviceaccording to the present invention. In this example, the disc 1 has arecord layer composed of phase change metal material. The drive deviceadjusts the laser output, controls the temperature of the record layer,and changes the crystal/non-crystal state so as to record data to thedisc 1.

[0080] The disc 1 is rotated and driven by a spindle motor 22. Anoptical pickup 23 records and reproduces data to/from the disc 1. Theoptical pickup 23 is traveled in the radius direction of the disc 1 by afeed motor 24.

[0081] Data is supplied from an external host computer 30 to the drivethrough an interface 29 (for example, SCSI (Small Computer SystemInterface)). An encoder/decoder block 25 is connected to the interface29. A buffer memory 26 is connected to the encoder/decoder block 25. Thebuffer memory 26 stores write data or read data.

[0082] The write data is supplied to the encoder/decoder block 25through the interface 29. When data is recorded, the encoder/decoderblock 25 generates data in the above-described format. Thereafter, theencoder/decoder block 25 encodes data corresponding to the format. Whendata is reproduced, the encoder/decoder block 25 performs a decodeprocess for the data and outputs digital data to the host computer 30through the interface 29. The encoder/decoder block 25 adds an addressto the data as a sub code and to a header of the data.

[0083] The encoder/decoder block 25 supplies the record data to a laserdriver 28 through an equalizer 27. The laser driver 28 generates a drivewaveform having a predetermined level necessary for recording data tothe disc 1. An output signal of the laser driver 28 is supplied to theoptical pickup 23. The optical pickup 23 records the data to the disc 1.The laser driver 28 properly controls the laser power corresponding toan APC (Automatic Power Control) operation of an RF signal processingblock 31. In addition, a signal corresponding to reflected light of thedisc 1 is supplied to the RF signal processing block 31. An addressextracting circuit 32 extracts address information from the signalsupplied from the RF signal processing block 31. The extracted addressinformation is supplied to a controlling microcomputer 33 (that will bedescribed later).

[0084] In the RF signal processing block 31, a matrix amplifiercalculates a detection signal of a photo detector and generates atracking error signal TERR and a focus error signal FERR. The trackingerror signal and the focus error signal are supplied to a servo block34.

[0085] The controlling microcomputer 33 controls a seek operation usingthe extracted address. In addition, the controlling microcomputer 33controls the laser power using a control signal. The controllingmicrocomputer 33 comprises a CPU (Central Processing Unit), a RAM(Random Access Memory), and a ROM (Read Only Memory). The controllingmicrocomputer 33 controls all the structural portions of the drive thatare the interface 29, the encoder/decoder block 25, the RF signalprocessing block 31, the servo block 34, and so forth. A memory 36 canbe connected to the controlling microcomputer 33.

[0086] An RF signal reproduced from the disc 1 is supplied to theencoder/decoder block 25. The encoder/decoder block 25 performs a decodeprocess corresponding to a predetermined format such as demodulationprocess for demodulating modulated record data and a decode process fordecoding error correction code (namely, error correction process). Theencoder/decoder block 25 stores reproduction data to the buffer memory26. When the encoder/decoder block 25 receives a read command from thehost computer 30, the encoder/decoder block 25 transfers the read datato the host computer 30 through the interface 29.

[0087] A frame synchronous signal, the tracking error signal, and thefocus error signal are supplied from the RF signal processing block 31to the servo block 34. In addition, address information is supplied fromthe address extracting circuit 32 to the servo block 34. The servo block34 performs a tracking servo operation and a focus servo operation forthe optical pickup 23. In addition, the servo block 34 performs a threadservo operation for the feed motor 24.

[0088] In the above example, the host computer 30 is connected to thedrive device. However, it should be noted that the present invention isnot limited to such a structure. Instead, another device can beconnected to the drive device as long as the connected device inputs andoutputs a digital signal and is compatible with the interface of thedrive device. For example, the drive device may be built in a portabledigital video camera recorder that records a photographed picture to adisc shaped record medium.

[0089] In the above example, format data for the disc 1 is generated bythe encoder/decoder block 25. However, the present invention is notlimited to such an example. In other words, the format data may begenerated by the controlling microcomputer 33. Alternatively, the formatdata may be supplied from the host computer 30.

[0090] Next, a second embodiment of the present invention will bedescribed. In the above example, a blank area of the area DAN-2 ismanaged as a file. An FE of a sub directory of the root directory andthe substance thereof are added by reducing the size of the EIF that hasbeen allocated in the format process as a dummy file in the area DAN-2.In contrast, according to the second embodiment of the presentinvention, a blank area of the area DAN-2 is managed in a memory.

[0091] The format of the disc 1 and the structure of the drive deviceaccording to the second embodiment are almost the same as thoseaccording to the first embodiment.

[0092] When a disc 1′ is formatted, an area DAN-1 and an area DAN-2 areformed. At that point, unlike with the first embodiment, a particularfile EIF for a blank area of the area DAN-2 is not formed. In otherwords, although a particular area as the area DAN-2 is allocated, adummy file for a blank area thereof is not placed. Thus, the SBD placedin the area DAN-1 represents that the area is a blank area.

[0093] When the disc 1′ that has been formatted in such a manner isloaded to the drive device or the power thereof is turned on, the drivedevice scans all the area DAN-2 and detects a blank area. The drivedevice stores information about the detected blank area as a blank areamanagement table to its memory. The blank area management table isstored to the memory 36 of the structure shown in FIG. 10. The blankarea management table contains a list of the start address or the endaddress and the length of the blank area.

[0094] The structure of the blank area management table is not limitedto such an example. Alternatively, the area DAN-2 may be scanned sectorby sector. As a result, bit map data with flags for individual sectorsmay be structured.

[0095] In other words, according to the second embodiment of the presentinvention, the AD about the blank area information of the area DAN-2 ismanaged in the memory. Thus, unlike with the first embodiment, it is notnecessary to allocate the EIF in the area DAN-2. As a result, it is notnecessary to place the FE of the EIF. Thus, the area DAN-2 can be moreeffectively used. In addition, since the blank area information of thearea DAN-2 is managed in the memory, data of the area DAN-2 can be morequickly changed. As a result, files and directories of the disc 1′ canbe quickly rewritten, added, and deleted.

[0096] According to the present invention, management information of thefile system such as information about the root directory and FEs andsubstances of sub directories are written together to the area DAN-2 ofthe disc 1′. Thus, when the disc 1′ is loaded to the drive or the powerthereof is turned on, the disc 1′ can be more quickly scanned so as togenerate the blank area management table than the case that suchinformation is placed on the disc.

[0097] As with the first embodiment, directories and files on the disc1′ are accessed corresponding to information of the area DAN-2. When afile or a directory is added, an element corresponding to information ofthe area DAN-2 is written in the blank area management table stored inthe memory. In addition, real information of the area DAN-2 of the disc1′ is rewritten.

[0098] The second embodiment of the present invention can be applied toa device that generally records data such as a personal computer. Morepreferably, the second embodiment of the present invention can beapplied to a dedicated device such as a portable digital video cameravideo reorder that records a photographed picture to a disc shapedrecord medium.

[0099] In addition, in the above example, the present invention isapplied to an attachable/detachable disc shaped record medium such as anoptical disc or a magneto-optical disc. However, it should be noted thatthe present invention can be applied to another type of a record mediumas long as recorded data is managed with particular managementinformation. For example, the present invention can be applied to afixed drive such as a hard disk drive.

[0100] As was described above, according to the present invention,names, addresses, lengths, and so forth of directories, files, and soforth managed on a disc are recorded together in a predetermined area(area DAN-2) on the disc. Thus, such management information can bequickly read.

[0101] In addition, according to the present invention, since names,addresses, lengths, and so forth of directories, files, and so forthmanaged on a disc are recorded in the area DAN-2, the time necessary forrestructuring files in the case that such information is destroyed dueto a particular reason can be shortened.

[0102] According to the first embodiment of the present invention, theblank area of the area DAN-2 is managed as a file. Thus, the area DAN-2can be restricted from being written by another OS.

[0103] In addition, according to the first embodiment of the presentinvention, when management information and the substance of a directoryare added, a file managed as a blank area is reduced for the addedinformation. Thus, it is not necessary to rewrite the substance of thedirectory.

[0104] According to the first embodiment of the present invention, whenthe area DAN-2 becomes full, by rewriting information about a filemanaged as a blank area of the area DAN-2, the area DAN-2 can beextended.

[0105] In addition, according to the first embodiment of the presentinvention, since a special attribute is assigned to a file managed as ablack area of the area DAN-2, the file managed by as a black area can beprevented from being deleted by another OS.

[0106] Although the present invention has been shown and described withrespect to a best mode embodiment thereof, it should be understood bythose skilled in the art that the foregoing and various other changes,omissions, and additions in the form and detail thereof may be madetherein without departing from the spirit and scope of the presentinvention.

What is claimed is:
 1. A recording method for recording data to a discshaped record medium corresponding to a hierarchical file system,comprising the steps of: recording management information for managingthe hierarchical structure of the file system to a predetermined area ofthe disc shaped record medium; and treating an unused area of thepredetermined area as a special file.
 2. The recording method as setforth in claim 1 , further comprising the step of: when the managementinformation is added to the predetermined area, reducing the size of thespecial file corresponding to the added management information andrecording the added management information to the blank area of thepredetermined area.
 3. The recording method as set forth in claim 1 ,wherein the information that represents the special file is placed at afixed location of the predetermined area.
 4. The recording method as setforth in claim 3 , wherein the fixed location is before the location ofthe information that represents a root directory of the hierarchicalstructure.
 5. The recording method as set forth in claim 3 , wherein thefixed location is after the location of the information that representsa root directory of the hierarchical structure.
 6. The recording methodas set forth in claim 3 , wherein the fixed location is at the boundaryof an area of the substance of a file represented by the managementinformation and the predetermined area.
 7. The recording method as setforth in claim 1 , further comprising the step of: when thepredetermined area becomes full for the management information,rewriting the information that represents the special file andincreasing the area of the special file.
 8. The recording method as setforth in claim 1 , further comprising the step of: designating a hiddenfile attribute, a system file attribute, and a read only attribute tothe special file.
 9. A recording apparatus for recording data to a discshaped record medium corresponding to a hierarchical file system,comprising: means for recording management information for managing thehierarchical structure of the file system to a predetermined area of thedisc shaped record medium; and means for treating an unused area of thepredetermined area as a special file.
 10. A disc shaped record mediumfor recording data corresponding to a hierarchical file system, whereinmanagement information for managing the hierarchical structure of thefile system is recorded at a predetermined area, and wherein an unusedarea of the predetermined area is treated as a special file.
 11. Therecord medium as set forth in claim 10 , wherein when the managementinformation is added to the predetermined area, the size of the specialfile is reduced corresponding to the added management information, andwherein the added management information is recorded in the blank areaof the special file.
 12. The record medium as set forth in claim 10 ,wherein the information that represents the special file is placed at afixed location of the predetermined area.
 13. The record medium as setforth in claim 12 , wherein the fixed location is before the location ofthe information that represents a root directory of the hierarchicalstructure.
 14. The record medium as set forth in claim 12 , wherein thefixed location is after the location of the information that representsa root directory of the hierarchical structure.
 15. The record medium asset forth in claim 12 , wherein the fixed location is at the boundary ofan area of the substance of a file represented by the managementinformation and the predetermined area.
 16. The record medium as setforth in claim 10 , wherein when the predetermined area becomes full forthe management information, the information that represents the specialfile is rewritten so as to extend the area of the special file.
 17. Therecord medium as set forth in claim 10 , wherein a hidden fileattribute, a system file attribute, and a read only attribute aredesignated to the special file.